Born at Epsom, Surrey, England, and died 6 th January, 1890, at St. Ives, Lane Cove, Sydney.
In England he was a gardener in the service of Lord Cornwallis. He was in charge of the Herbarium, Botanic Gardens, Sydney in 1857, during von Mueller’s visit to Sydney. He assisted Mueller in collecting for the “Flora Australiensis.” Bentham mentions his name. Mueller says, in dedicating an Ionidium to him-
“In choosing that (name) here adopted, the author wishes to express a mark of acknowledgment for much aid which; in forming collections of plants in the classical fields around Port Jackson, he received from Mr. W. Vernon of Sydney.” (Pl. Vict. i. 223).
He was a constant correspondent of the Baron for 30 years. After leaving the Botanic Gardens he became gardener to Mr. T.S. Mort of Darling Point, whose garden was the finest private establishment in Sydney at that time.
Ionidium vernonii, F.v.M., commemorates him.
Source: Maiden, J.H. (1908) Records of Australian botanists- (a) General, (b) New South Wales. Journal and Proceedings of the Royal Society of New South Wales for 1908. 42:60-132